GMC FC150 high beam and low beam headlight bulbs both utilize the H6006 size. The replacement chart covers 1950 to 1952 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC FC150 uses the H6006 bulb type across all listed model years for both high beam and low beam headlight positions, making it the sole bulb type present in these specifications.
The H6006 is an ANSI-standardized sealed beam unit recognized in both the United States and Canada, meaning its physical and electrical characteristics conform to a defined national standard rather than a proprietary specification.
A sealed beam unit integrates the filament, reflector, and lens into a single fused glass assembly. Because these components are not separable, the entire unit is replaced rather than an individual bulb.
The H6006 operates at 12 volts, which is consistent with the standard electrical system voltage found in most passenger and light commercial vehicles of that era.
The H6006 unit has a 5x7-inch rectangular form factor. This shape was a common standardized format that allowed interchangeability across different makes and models using the same specification.
For the GMC FC150, the H6006 specification applies uniformly to the 1950-1952 model years, with no variation in bulb size between those years or between the high and low beam positions.
Because both the high beam and low beam positions share the same H6006 specification, the FC150 used a dual-filament or combined sealed beam arrangement rather than separate units for each function.